Grate bar



c. R. W

. April 14, 1931.

GRAI'E BA Filed Dec. 6, 1928 Inventor 51 Wadi A llor "=9 Patented Apr.14, 1931 catvm fie. WAID, or BIRMINGHAM, ALABAM v 'GRATE BAR Applicationfiled December 6, 1928. Serial No. 324,098.

. My invention relates to grate bars of the type in which a rockingassembly bar 'is'provided and adapted to receive astride it a'pluralityof independently removable grate segments, each comprisin a base adaptedto straddle the assembly dJar and a fire head preferablyintegral withsuch base.

- Grates of the character above. described, are generally denominatedinterchangeable grates, and it is of especialmoment that the gratesegments should be standardand therefore interchangeable and that theyshould be of such type as to be readily removable vertically withoutdisturbing the assembly bar, and that they should be associated withmeans which will suitably space and effectually brace their fire heads.I My presentinvention embodies all of the advantages above described andinvaddition thereto provides grate units which comprise a single firehead and base, cast integral, with the fire head composed of a zigzagele e 7 v i r arrangmg the upper portion of the fire head 1 whichcrossesthe assembly bar at an acute angle to its long axis, said fire headshaving at their ends lateral bosses which abut, thus spacing and bracingtheir free ends.

Another feature of my lnventlon relates to the arrangementfor thespacing bosses disposed on opposite sides of the saddle, these bossesbeing arranged withdownwardly sloping convex upper surfaces emergingsymmetrically from opposite sides of the fire head near its base, bothsides converging towards the center line of the assembly bar and ter- 5minating in vertical'faces lying in planes at right angles to said axis;Theseabutting shoulders thus provided engage throughout the length ofthe assembly bar and serve to hold the segments in correct operatingposition.

V A further feature of my invention resides in casting the saddlebase sothat it will take .a bearing on the top edgeof the assembly bar andwill, by virtue of the'presence of off-sets and tapering portions haveonly ,a bottom,

bearing on each side of the assembly bar, whereby the base casting isshaped to stand clearof the assembly bar except at itstop and 0 bottompoints ofcontact, making it practi serve as SPELCBI'S.

for all types of fire boxes' fication, and in which cally unnecessary tomachine the saddle por .tion to remove small irregularities. n

More particularly my invention comprises a grate. segment castingcomprising a body portion which is thin, which tapers in thicknessdownwardlyfrom the top of the fire head to its bottom edge, and whichincreases. in width from top to bottom as it approaches its centralportion. The thin body being shaped to present zig-zagfirehead ofsymmetrical and preferably uniform conformation With its dependingcenter portion thickened sufficiently to provide asaddle having parallelvertical faces adapted by engaging corresponding faces ofadjacent'segment to My invention furthercontemplates cutting ,away theintermediate portions of the side abutment faces on the segmentsaddlesto reduce the necessity for grinding and machine work infinishing the castings. 1

A further feature of my invention lies in including theend abutmentsin aplane above the base portion of the fire head from which base portion ofthe saddle to be maintained as a standard and the upper portion formingthe fire head to be cast with various modifi cations, according to theduty required, which can be accomplished by sectional patterns vthesaddle; depends, thereby permitting the i having;interchangeable top.portions for forming the variable upper portion of the fire head. Bylthls arrangement, and at a greatly reduced exp f patterns; a W

rietyof grate segment castingscan beha'd My invention also contemplatesgivingfa zigzag fire. head a :top surface, the'major intermediateportion of which is convex and the .end portionsof whi'c'h' preferablyrise towards the free ends ofsaid fire head. My invention also comprisesthe novel. de-

tails of construction and arrangements of 7 parts, whichin theirpreferred'embodiments ,only. are illustrated in the accompanyingdrawings which form'a part of this speci- Fig. '1 is a plan view br nassembly bar showing. individual grate segments assembled the, sections12 and 18.

on the ends thereof with the intermediate group of segments omitted.

Fig. 2 is a side elevation of one end of the assembled grate bar shownin Fig. 1.

Fig. 3 is an enlarged cross-sectional View, taken on the line IIIIII ofFig. 2, showing a support in side elevation.

Similarreference numerals refer to similar parts throughout thedrawings.

According to the embodiment illustrated I show an assembly bar 4,preferably adapted to rock by being provided at each end with anupturned portion 5 bearing a trunnion 6. The assembly bar in crosssection is seen more clearly in Fig. 3, and comprises a rounded topportion 7 and abase portion 8 which has its side walls 9 preferablydisposed to flare outwardly at a slight angles and which is undercut, at10 to reduce weight by the removal of superfluous metal.

The side faces of the assembly bar are preferably uninterruptedlongitudinally thereof, thereby permitting the grate seg ments to bereadily mounted thereon and slid lengthwise therealong until they abutand assume their working position.

The interchangeable grate sections are all alike except that one or moremay have cast integral therewith a depending arm 11 adapted to beconnected'at its lower end to a grate shaking bar, not shown. Except inrespect of this. arm 11, the grate segments whichadjoin and' form thefire head which is convex over the sections 13' to 17, inclusive, andwhich rises slightly outwardly over These sections '12 and 18 areprovided on each side face with an offset shoulder 19 having adownwardly tapering bottom edge 20, which shoulders are wide enough toabut, as shown in Fig. 1,, when the segments are in assembled positionon the bar-4. 'Each of the segment sections decreases in thicknessdownwardly so as to have the proper draft and it will be observedthatthe sections 12 and 18' have their bottom edges slanting upwardlyand inwardly, while the sections 13. and 17 have their bottom edgesextending down as they approach the sections 14 and 16, respectively,and thatthe bases of these latter sections extend down further to thebottom of what I term the saddle portion of the segment, which portionis formed.

This

ruption of these faces leaves a depression indicated in Fig. 3. a

- Thedescription of the obverse face of Fig. 3 applies equally to thereverse face of this figure when the. segmentis turned'abouta verticalaxis 180. I i U The saddle formed by the'enl arged shouldered portions21 is provided with a recess shaped. at its upper end to receive the,top edge 7 of the assembly bar and at itsbottom to conform to the baseportion 8 of the as sembly bar except-that its side edges are preferablyparallel so as to. have-only a point contact near thebase of each side 9ofthe bar. Also the saddle recess is enlarged so as to jacent to itsthree points of contact.

It will be observed that the point 22 lies be,-

low a horizontal plane indicated at .X--Y i Fig. 3, whichpracticallybisects the segment, the portion above said planeconstituting the firehead and that below the line, the base and saddle portions. The purposein this con.- struction is to bring below this line all of the saddleand base portion of the segment; and to leave above the line only thefire head proper with its end abutment-s 19. .With such a design it willbe seen that in casting these seg ments the patterns may have the topportion above the line detachable from the. base portions sothatinterchangeable top pattern sectionscan be used to cast the fire. headto adapt it to the furnace where it is to beused without requiring anyvariation in the standard assembly bar and segment base. This is clearthe'assembly bar except opposite or adof material valuein reducing thepattern cost by allowing great flexibility in design.

It will be observed that the grate segment section 15,.which' isat thecenter of the grate segment, straddles the assembly bar 4, passingoversameat an angle and that it is reinforced throughout by theshoulders. 21

panel.

The segments when assembled will have their shoulders 19 and 21 abuttingthrough out, thus givin'gthem engagement at the center and on each sideat then free ends. They provide gradually increasing downward clearanceforthe'escape ofashes and their zigzag treads as they rock ,Will passunder allfof the "fire bed, thus leaving 'no part thereof from which,as'the grate rocks, the ashes may "not fall'freely and be discharged.While the I which extend, the full width of this middle I castingforming the grate segment, except where shouldered, is quite thin, itswidth from top to bottom is carefully designed to give it ample strengthto Withstand all normal working stresses.

Though I have described with great particularity the details of theembodiment of the invention herein shown, it is not to be construed thatI am limited thereto, as changes in arrangement and substitution ofequivalents may be made by those skilled in the art without departingfrom the invention as defined in the appended claims.

What I claim as new, is

1. A grate bar segment formed of a thin casting having zig-zag shapeinplan with its central section shouldered symmetrically on opposite sidesto form a saddle having opposite parallel faces flattened to formvertical abutment surfaces interrupted betweentheir upper and lowerportions, the top of the shoulder on each side of the section slopingdownwardlyand outwardly from its juncture I with said section.

2. A grate segment composed of seven thin vertical panels arranged inzig-zag relation as viewed in plan, the panels being of substantiallyequal width and all downwardly tapered with the five center panelsconvex overhead and the'end panels being of greater length verticallyalong their free edges than along their inner edges the end and centerpanels being provided with bosses to abut adjacent grate segments. I

3. In a grate of the character embodying an assembly bar and a pluralityof grate bar segments straddling the assembly bar, grate bar segmentseach comprising a firehead and a base, the firehead being zig-zag inplan and being enlarged at its ends to abut adjacent ends of fireheads,and the base being provided with bosses at its sides to abut the basesof adjacent segments, the abutting portions providing for continuousopenlng from end to end between adjacent fireheads.

In testimony whereof I aflix my signature.

CALVIN R. WAID.

